1. Field of the Invention
The present invention relates to roof flashing assemblies for accomodating the passage of various pipes, tubes and utility conduits, such as electrical, air venting, and water piping, through the roof of a building in a weatherproof fashion, and, more particularly, to a multiple passage roof flashing and counterflashing assembly.
2. Description of the Prior Art
Various methods and techniques have been employed in the prior art to bring various pipes, tubes, and utility conduits through the roofs of building for either venting to the atmosphere or for connection to the particular utility service in a trouble-free, leakproof fashion.
One major problem associated with the prior art is the need to reduce the number of roof openings. The prior art is typically characterized by the use of roof flashing assemblies which permit but one pipe, tube or conduit through such assembly. By reducing the number of roof openings, not only is the likelihood of roof leakage reduced when it rains, but the number of roof flashing assemblies is correspondingly reduced as well. Such a reduction in the number of roof flashing assemblies effectuates a significant cost savings in the erection of the building structure.
Another problem frequently encountered in the prior art is the installation of additional pipes and conduits after the building structure has been erected and the roof finished. In such a case, one or more additional openings had to be made in the roof, an additional roof flashing assembly installed and the piping or conduit passed therethrough. Such retrofit modifications or additions are not only costly, but are time-consuming as well. Nevertheless, such after-the-fact installations occur with great frequency, and, are lamentably expected by both the builder and the owner.
The problem of electrolysis and its deleterious effects upon utility conduits and, especially plumbing piping, is well-known in the prior art. Metal-to-metal contact of different metals must be avoided if the familar metallic ion migration from one metal to the other is to be avoided. Such electrolysis is found to exist in the prior art roof flashing assemblies.